3. Current issues

In this sections the current issues are outlined that require further
investigation.

3.1. Fonts

The font path and glyphs need to be the same for the front-end and
each of the back-end servers. Font glyphs could be sent to the back-end
servers as necessary but this would consume a significant amount of
available bandwidth during font rendering for clients that use many
different fonts (e.g., Netscape). Initially, the font server (xfs) will
be used to provide the fonts to both the front-end and back-end servers.
Other possibilities will be investigated during development.

3.2. Zero width rendering primitives

To allow pixmap and on-screen rendering to be pixel perfect, all
back-end servers must render zero width primitives exactly the same as
the front-end renders the primitives to pixmaps. For those back-end
servers that do not exactly match, zero width primitives will be
automatically converted to one width primitives. This can be handled in
the front-end server via the GC state.

3.3. Output scaling

With very large tiled displays, it might be difficult to read the
information on the standard X desktop. In particular, the cursor can be
easily lost and fonts could be difficult to read. Automatic primitive
scaling might prove to be very useful. We will investigate the
possibility of scaling the cursor and providing a set of alternate
pre-scaled fonts to replace the standard fonts that many applications
use (e.g., fixed). Other options for automatic scaling will also be
investigated.

3.4. Per-screen colormaps

Each screen's default colormap in the set of back-end X servers
should be able to be adjusted via a configuration utility. This support
is would allow the back-end screens to be calibrated via custom gamma
tables. On 24-bit systems that support a DirectColor visual, this type
of correction can be accommodated. One possible implementation would be
to advertise to X client of the DMX server a TrueColor visual while
using DirectColor visuals on the back-end servers to implement this type
of color correction. Other options will be investigated.